Just as researchers in Scotland say Brain Ageworks, researchers in France say it doesn't. According to data from University of Rennes, Brittany, Brain Age failed to show any significant jump in memory.

The research had a sample of ten year-old children split into four groups: The first two groups did a seven-week DS memory course, the third group did puzzles with pencil and paper, while the fourth group just went to school as regular. Before and after started each program, the groups did logic tests.

The results? The DS control group did not do significantly better — save for a 19 percent increase in math. (However, the pencil-and-paper group also had the same increase in math, and the just-go-to-school group had a 18 percent increase in math.) However, the pencil-and-paper group showed a 33 percent increase in memorization, while the DS groups did 17 percent worse. The kid who just went to school showed a 20 percent increase.

According to Alain Lieury, professor of cognitive psychology at the University of Rennes, "The Nintendo DS is a technological jewel. As a game it's fine, but it is charlatanism to claim that it is a scientific test... There were few positive effects and they were weak. Dr Kawashima is one of a long list of dream merchants."

Professor Lieury is publishing his findings in a new book, Stimulate Your Neurones, which is out this month.